1. Field of the Invention
This invention relates to a novel squid chitin formed material, and, more particularly, to a squid chitin formed material, such as a squid chitin sheet, a squid chitin fiber, and the like. The squid chitin formed material has excellent characteristics such as superior strength and the like.
2. Description of the Background
Since formed materials made of chitin are in vivo decomposable, they are widely used as suture threads, wound covering or protecting materials, dialysis membranes, molecular filters, ultra-membrane filters, and the like.
According to a conventionally known method for preparing materials formed of chitin, exoskeletons of a crustacean or an insect are first treated with hydrochloric acid and sodium hydroxide, and chitin separated is formed into a sheet or the like (Japanese Patent Laid-open Nos. 53339/1986, 64256/1986, 129005/1986, and 212302/1986).
Chitins made from exoskeletons of crustacean or insects, however, exhibit only poor dope forming capability, resulting in formed chitin materials having inadequate characteristics such as insufficient strength, reduced elongation, or the like. Thus, chitins produced from conventional sources have problems still to be solved. In an attempt to improve the insufficient chitin properties, Japanese Patent Laid-open Nos. 53339/1986 and 64256/1986 propose to employ a water soluble polymer as a binder. This method, however, does not necessarily provide a satisfactory solution.
In view of this situation, the present inventors have undertaken extensive studies in order to solve the above problems, and found that among chitins produced from a number of raw materials squid chitins made from squid crust possessed excellent characteristics. The inventors have further found that among squid chitins those produced from squid galadius of Mollusca, Teuthoidea, had exceptionally superior characteristics, and could be formed into superb chitin sheets and the like. Such a finding has led to the completion of this invention.